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//
// Copyright (C) 2009 The Android Open Source Project
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
//
#include "update_engine/payload_consumer/extent_writer.h"
#include <errno.h>
#include <sys/types.h>
#include <unistd.h>
#include <algorithm>
#include "update_engine/common/utils.h"
#include "update_engine/payload_consumer/payload_constants.h"
using std::min;
namespace chromeos_update_engine {
bool DirectExtentWriter::Write(const void* bytes, size_t count) {
if (count == 0)
return true;
const char* c_bytes = reinterpret_cast<const char*>(bytes);
size_t bytes_written = 0;
while (count - bytes_written > 0) {
TEST_AND_RETURN_FALSE(next_extent_index_ < extents_.size());
uint64_t bytes_remaining_next_extent =
extents_[next_extent_index_].num_blocks() * block_size_ -
extent_bytes_written_;
CHECK_NE(bytes_remaining_next_extent, static_cast<uint64_t>(0));
size_t bytes_to_write =
static_cast<size_t>(min(static_cast<uint64_t>(count - bytes_written),
bytes_remaining_next_extent));
TEST_AND_RETURN_FALSE(bytes_to_write > 0);
if (extents_[next_extent_index_].start_block() != kSparseHole) {
const off64_t offset =
extents_[next_extent_index_].start_block() * block_size_ +
extent_bytes_written_;
TEST_AND_RETURN_FALSE_ERRNO(fd_->Seek(offset, SEEK_SET) !=
static_cast<off64_t>(-1));
TEST_AND_RETURN_FALSE(
utils::WriteAll(fd_, c_bytes + bytes_written, bytes_to_write));
}
bytes_written += bytes_to_write;
extent_bytes_written_ += bytes_to_write;
if (bytes_remaining_next_extent == bytes_to_write) {
// We filled this extent
CHECK_EQ(extent_bytes_written_,
extents_[next_extent_index_].num_blocks() * block_size_);
// move to next extent
extent_bytes_written_ = 0;
next_extent_index_++;
}
}
return true;
}
} // namespace chromeos_update_engine